PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “NALIDIXIC ACID”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 955 records · Page 53Linked to original sources
PubMed1992

Efficacy of norfloxacin for shigellosis: a double-blind randomised clinical trial.

In a double-blind, randomised, clinical trial on 122 adults with acute Shigella dysentery, 60 patients were treated with norfloxacin and 62 with nalidixic acid. Of these, 32 patients in the norfloxacin group and 28 patients in the nalidixic acid group had Shigella in their stool. Patients of the two treatment groups were clinically comparable on admission. No significant differences in clinical responses were observed in the two groups among the Shigella-positive cases, Shigella-negative cases and among the total cases. All isolates of Shigella were susceptible to norfloxacin, whereas 13.8% of the strains were resistant to nalidixic acid.

Adult↗
PubMed1998

Reversible induction of ATP synthesis by DNA damage and repair in Escherichia coli. In vivo NMR studies.

Early metabolic events in Escherichia coli exposed to nalidixic acid, a topoisomerase II inhibitor and an inducer of the SOS system, were investigated by in vivo NMR spectroscopy, a technique that permits monitoring of bacteria under controlled physiological conditions. The energetics of AB1157 (wild type) and of its isogenic, SOS-defective mutants, recBC, lexA, and DeltarecA, were studied by 31P and 19F NMR before, during, and after exposure to nalidixic acid. The content of the NTP in E. coli embedded in agarose beads and perfused at 36 degreesC was found to be 4.3 +/- 1.1 x 10(-18) mol/cell, yielding a concentration of approximately 2.7 +/- 0.7 mM. Nalidixic acid induced in the wild type and mutants a rapid 2-fold increase in the content of the NTP, predominantly ATP. This induction did not involve synthesis of uracil derivatives or breakdown of RNA and caused cell proliferation to stop. Removal of nalidixic acid after 40 min of treatment rescued the cells and resulted in a decrease of ATP to control levels and resumption of proliferation. However, in DeltarecA cells, which were more sensitive to the activity of the drug, ATP elevation could not be reversed, and ATP content continued to increase faster than in control cells. The results ruled out association between the elevation of ATP and the induction of the SOS system and suggested involvement of a process reminiscent of apoptosis in the stimulation of ATP synthesis. Thus, the presence of the RecA protein was found to be essential for reversing the ATP increase and cell rescue, possibly by its function in repair of DNA damage.

Adenosine Triphosphate↗
PubMedDate not supplied

[Antibiotic sensitivity of bacteria isolated from the urine of children with urinary tract infections from 1986 to 1995].

In adults and in children urinary system infections are mostly caused by gram-negative and rarely by gram-positive bacteria. Of gram-negative bacteria the most frequent cause of infections are Escherichia coli, Klebsiella species, Proteus mirabilis, Pseudomonas aeruginosa, Acinetobacter, Serratia etc., and of gram-positive bacteria Enterococcus, Staphylococcus, Streptococcus agalactiae. In rare cases the cause of infection may also be Pneumococcus and Haemophilus influenzae. AIM OF THE STUDY: The aim of the study was to investigate the sensitivity to antibiotics of gram-negative bacteria as the predominant cause of urinary infections. METHOD OF THE STUDY: We isolated 20,615 bacterium species from urine of children hospitalized or treated as outpatients at the University Children's Hospital in Belgrade. Urine was collected classically, i.e. by taking the second clean stream into a sterile test tube or by Uricult test. The samples were cultured on blood plates and endo-agar. Identification was done by standard bacteriologic methods and when findings were dubious API-20E (bioMerieux) was used. Bacterium sensitivity to nine antibiotics (ampicillin, cephalexin, cefotaxime, chloramphenicol, gentamicin, amikacin, co-trimoxazole, nalidixic acid and nitrofurantoin) was assessed with disc diffuse method on Müller-Hinton agars. RESULTS: Based on the obtained results, Escherichia coli species sensitivity to amikacin, gentamicin, cefotaxime, nalidixic acid and nitrofurantoin ranged from 90 to 100%; sensitivity to co-trimoxazole and chloramphenicol ranged from 70 to 80%, to cephalexin from 50 to 60%, while to ampicillin it was only 20%. Klebsiella species sensitivity to nalidixic acid and cefotaxime was 70-85%; to amikacin, cefotaxime, co-trimoxazole and gentamicin 60-80%; to cephalexin and chloramphenicol 40-50%, and to ampicillin only 5-15%. Proteus species showed sensitivity to amikacin, gentamicin, cefotaxime and nalidixic acid of 90-95%; to co-trimoxazole and chloramphenicol 70-80%; to cephalexin and ampicillin 40-50%, and to nitrofurantoin 10%. Pseudomonas aeruginosa species showed the highest level of sensitivity to amikacin (40-50%), and somewhat lower to gentamicin (10-40%), and a very low sensitivity to other antimicrobial drugs (10-25%). DISCUSSION: It may be noted from the above data that gram-negative bacteria are the cause of urinary infections in about 90% of cases, while gram-positive bacteria are the cause in only 10%, which is in accordance with data from literature. Of all antibiotic drugs ampicillin (a wide spectrum penicillin) had a very significant role in the therapy of urinary infections. However, the long-term usage of ampicillin led to increased resistance to the drug in infections caused by Escherichia coli. Natural resistance to ampicillin of Klebsiella species limited its usage when penicillin was first introduced. Proteus mirabilis species, especially those isolate in primary infection, are often sensitive to amino penicillin. Contrary to Proteus mirabilis, indole-positive Proteus and Providentie species show a high resistance to these antibiotics. Due to the crisis in our country and the lack of other antibiotics, ampicillin was widely used. The wide use of the drug caused evident resistance of Escherichia coli and Proteus mirabilis to this antibiotic. A fall in the sensitivity of Klebsiella to cephalexin, gentamicin, amikacin and co-timoxazole, which occurred in 1992, has been explained by intrahospital circulation of multiresistant Klebsiella species. The sensitivity of isolated gram-negative bacteria Escherichia coli, Klebsiella species, Proteus mirabilis and Pseudomonas aeruginosa was the most prominent to aminoglycosides (amikacin and gentamicin). The most frequent mechanism of enterobacterial resistance to trimethoprim and co-trimoxazole involves dihydrofolate reductase enzyme. Comparative studies related to the administration of co-trimoxazole have shown that the difference in the efficacy between thes

Bacteria↗
PubMed1999

Relationship between haemolysis production and resistance to fluoroquinolones among clinical isolates of Escherichia coli.

The activities of ampicillin, amoxycillin-clavulanic acid, gentamicin, tetracycline, nalidixic acid, ciprofloxacin, pefloxacin and trovafloxacin against 207 consecutive clinical isolates of Escherichia coli were determined. Fifty-six (27.3%) isolates were haemolytic. The percentages of resistance to quinolones and tetracycline, but not to other agents, among haemolytic isolates were significantly lower (P < 0.05) than among non-haemolytic isolates. Ciprofloxacin-resistant mutants obtained from ciprofloxacin-susceptible haemolytic isolates still produced haemolysis. It is concluded that most quinolone-resistant clinical isolates of E. coli are non-haemolytic, although haemolysis is produced by quinolone-resistant mutants derived from haemolytic quinolone-susceptible strains.

Amoxicillin↗
PubMed1997

Biological activity of new aza analogues of quinolones.

A series of novel derivatives of 4H-pyrido[1,2-]pyrimidine, 1,4-dihydro-4-oxo-1,5-naphthyridine and 1,4-dihydro-4-oxo-1,6-naphthyridine were prepared and their biological activity was compared with that of nalidixic acid. The in vitro antibacterial activity of the tested compounds was lower than that of nalidixic acid except for two agents, 1b and 2c, with a higher activity against Enterococcus faecalis. The compounds were tested for their ability to cure four plasmids from two species of Enterobacteriaceae. The derivatives eliminated three plasmids (pKM101, pBR322, F'lac) at one-half or one-quarter of the minimal inhibitory concentration. Plasmid RP4 was unaffected by the treatment. None of these compounds showed better antichloroplast activity than nalidixic acid.

Animals↗
PubMed2002

Molecular epidemiology of nalidixic acid-resistant campylobacter isolates from humans and poultry by pulsed-field gel electrophoresis and flagellin gene analysis.

To investigate the potential of poultry products as the source of human infections associated with quinolone-resistant campylobacters, 140 human and 75 poultry isolates of nalidixic acid-resistant campylobacters were collected between 1996 and 1998, and analysed by two molecular typing methods. By the analysis of restriction fragment length polymorphism of the flagellin gene, 33 distinct patterns were obtained, with 18 of which shared by both human (89%) and poultry (93%) isolates. By the pulsed-field gel electrophoresis of SmaI-restricted macrofragments, 105 different profiles were obtained, and 11 were found in both human (40%) and poultry (23%) isolates. When the two typing methods were combined, 112 unique genotypes were obtained, 11 of which were shared by both populations, including 53 (38%) human isolates and 14 (19%) poultry isolates. Although domestic poultry products are still important sources of the quinolone-resistant campylobacter infections in humans, there are other factors that might contribute to these increasing infections simultaneously. A more stringent policy in the use of antimicrobial agents in food animals can no longer be ignored.

Animals↗
PubMed1988

Studies on DNA topoisomerase activity during in vitro chromatin assembly.

The in vitro assembly of chromatin, promoted by the Xenopus cell-free extract (S-150), can be inhibited by oxolinic acid and to a lesser extent by nalidixic acid. Both of these antibiotics have been shown to block the activity of the specialized type II Topoisomerase, bacterial DNA Gyrase. Oxolinic acid induces a DNA cleavage by Micrococcal Nuclease at specific sequences in the multiple cloning vector pGEM-4. Nalidixic acid does not inhibit DNA supercoiling, but does diminish the extent of chromatin formation achieved by the S-150 on circular DNA templates. The Topoisomerase I inhibitor, berenil, does not inhibit extensive chromatin assembly, although it does diminish the level of supercoiling. Taken together, these results suggest that both topoisomerases play a role in the assembly process. Topoisomerase I may catalyze both the introduction of unconstrained supercoils into relaxed DNA and the formation of monosomes, while Topoisomerase II may promote extended chromatin assembly.

Animals↗
PubMed1975

Rate stimulation of deoxyribonucleic acid synthesis after inhibition.

The degree to which the rate of deoxyribonucleic acid synthesis in thy- cultures of Escherichia coli is stimulated after a period of thymine starvation is shown to be a function of the concentration of thymine present as well as of the culture doubling time. Inhibition of deoxyribonucleic acid synthesis by nalidixic acid yields comparable results. Periods of thymine starvation exceeding one doubling time appear to cause an irreversible inactivation of a fraction of the replication forks in the culture.

Carbon Radioisotopes↗
PubMed2004

Characterization of the susceptibility of mycobacteria in BACTEC 12B media containing PANTA that had been supplemented with ceftazidime, and characterization of the individual components of PANTA in the presence of C18-carboxypropylbetaine.

C(18)-carboxypropylbetaine (CB-18) specimen processing has enhanced the diagnosis of mycobacterioses by smear, culture, and nucleic acid amplification. However, toxic side effects of CB-18 in liquid culture, especially in the presence of antibiotics, have been reported. The interaction of CB-18 at 20-25 microg/ml with the individual components of the antibiotic supplement PANTA that had been fortified with ceftazidime (PANTA-caz) was characterized in BACTEC 12B cultures using four mycobacterial isolates. When the Mycobacterium tuberculosis isolate ATCC 27294 was examined CB-18 plus PANTA-caz did not significantly alter the time-to-positive (i.e., time to a growth index (GI) of 15 (GI(15))), but did significantly increase the time to a GI of 500 (GI(500)) by approximately 8.5 days. This result could be attributed primarily to nalidixic acid, but also to ceftazidime to a lesser degree. Statistically significant increases in GI(15) of 12.5 days and GI(500) of 16.5 days were observed in the presence of CB-18 plus PANTA-caz with the Mycobacterium avium isolate ATCC 25291. These increases were due exclusively to trimethoprim. Statistically significant increases of approximately 2.5 and 9 days in GI(15) and GI(500), respectively, were observed with Mycobacterium kansasii ATCC 12478 in CB-18 plus PANTA-caz. The presence of nalidixic acid and ceftazidime were responsible for these alterations. When the behavior of the Mycobacterium fortuitum isolate ATCC 6841 was investigated in CB-18 plus PANTA-caz, significant increases in GI(15) of 8.5 days and GI(500) of 13 days were observed. The additive effects of nalidixic acid and azlocillin were responsible for these results. No single component of the PANTA-caz formulation was responsible for the interaction between CB-18 and PANTA-caz, although nalidixic acid contributed to these effects most often. These findings are consistent with the previous recommendation that CB-18 specimen processing follow a dilution-based format to ensure that the concentration of CB-18 carried-over into liquid media falls below 5-10 microg/ml.

Anti-Bacterial Agents↗
PubMed1992

Intergeneric natural plasmid transformation between E. coli and a marine Vibrio species.

Natural transformation is the mechanism of procaryotic gene transfer that involves the uptake and expression of genetic information encoded in extracellular DNA. This process has been regarded as a mechanism to transfer genes (primarily chromosomal markers) between closely related strains or species. Here we demonstrate the cell-contact-dependent transfer of a non-conjugative plasmid from a laboratory E. coli strain to a marine Vibrio species, the first report of intergeneric natural plasmid transformation involving a marine bacterium. The nucleic acid synthesis inhibitors nalidixic acid and rifampicin inhibited the ability of the E. coli to function as a donor. However, dead cells also served as efficient donors. There was an obligate requirement for cell contact. No transfer occurred in the presence of DNase I, when donors and recipients were separated by a 0.2-micron filter, or when spent medium alone was used as a source of transforming DNA. These results indicate that contact-mediated intergeneric plasmid exchange can occur in the absence of detectable viable donor cells and that small non-conjugative plasmids can be spread through heterogeneous microbial communities by a process previously not recognized, natural plasmid transformation. These findings are important in the assessment of genetic risk to the environment, particularly from wastewater treatment systems and the use of genetically engineered organisms in the environment.

Bacterial Adhesion↗
PubMed1977

Regulation of murein biosynthesis and septum formation in filamentous cells of Escherichia coli PAT 84.

Both the beta-lactam antibiotic, cephalexin, and the deoxyribonucleic acid synthesis inhibitor, nalidixic acid, are known to inhibit cell division in Escherichia coli and induce the formation of filaments. The biosynthesis of murein was investigated in these filaments and compared with the murein synthesized by the normally dividing rods of E. coli PAT 84. Differences were found in the extent of peptide side-chain cross-linkage. Filamentous cells had higher extents of cross-linkages in their newly synthesized murein. Quantitative analyses of the D-alanine carboxypeptidase and transpeptidase reactions in the different cells revealed that the carboxypeptidase activity of the filamentous cells was partially inhibited. These results were similar to those previously found with filaments that were obtained after growth of the thermosensitive division mutant at its restrictive temperature. We conclude that the formation of new cell ends (septa) depends on the proper balance between the activities of the D-alanine carboxypeptidase that regulates the availability of precursor doners and the transpeptidase, which catalyzes cross-linking and attachment of newly synthesized murein.

Alanine↗
PubMed1976

Effect of deoxyribonucleic acid replication inhibitors on bacterial recombination.

Two inhibitors of replicative deoxyribonucleic acid (DNA) synthesis, nalidixic acid (NAL) and 6-(p-hydroxyphenylazo)-uracil (HPUra), showed different effects on genetic recombination and DNA repair in Bacillus subtilis. Previous work (Pedrini et al., 1972) showed that NAL does not interfere with the transformation process of B. subtilis. The results reported in this work demonstrated that the drug was also without effect on the transfection by SPP1 or SPO-1 phage DNA (a process that requires a recombination event). The drug was also ineffective on the host cell reactivation of ultraviolet-irradiated SPP1 phage, as well as on transfection with ultraviolet-irradiated DNA of the same phage. HPUra instead markedly reduced the transformation process, as well as transfection, by SPO-1 DNA, but it did not affect the host cell reactivation of SPO-1 phage. In conclusion, whereas the NAL target seems to be specific for replicative DNA synthesis, the HPUra target (i.e., the DNA polymerase III of B. subtilis) seems to be involved also in recombination, but not in the excision repair process. The mutations conferring NAL and HPUra resistance used in this work were mapped by PBS-1 transduction.

Bacillus subtilis↗
PubMed1999

Incidence of quinolone resistance over the period 1986 to 1998 in veterinary Salmonella isolates from Germany.

A total of 24,591 nonhuman salmonella strains isolated in Germany between 1986 and 1998 were examined for their resistance to nalidixic acid by an agar diffusion method. The rate of resistance (inhibition zone, </=13 mm) ranged from 0.2% in 1986 to a peak of 14. 8% in 1990. Between 1991 and 1998 the MICs for nalidixic acid-resistant strains ranged from more than 256 microg/ml for nalidixic acid to between 0.25 and 128 microg/ml for enrofloxacin. In the early 1990s a particularly high incidence of fluoroquinolone resistance (49.5%) was seen among isolates of Salmonella enterica serotype Typhimurium (Salmonella Typhimurium) definitive phage type 204c that mainly originated from cattle. Among isolates from poultry an increase in the incidence of nalidixic acid resistance to a peak of 14.4% was observed in 1994. This peak was due to the presence of specific resistant serotypes, mainly serotypes Hadar, Saintpaul, Paratyphi B (D-tartrate positive; formerly serotype Java) and Newport. Such strains exhibited a decreased susceptibility to enrofloxacin (MIC, 1 microg/ml). Among isolates from pigs the peak incidence of resistance was reached in 1993, with 7.5% of isolates resistant to nalidixic acid and enrofloxacin. The study demonstrates an increase in the incidence of strains that are resistant to nalidixic acid and that have decreased susceptibility to enrofloxacin after the licensing of enrofloxacin. In addition, the number of other serotypes that exhibited nalidixic acid resistance or reduced enrofloxacin susceptibility increased among the total number of isolates investigated between 1992 and 1998.

Animals↗
PubMed1998

[Antibacterial activity of ofloxacin in urine for 4 days after a single oral dose of 400 mg].

Antibacterial activity of ofloxacin in urine after a single oral dose of 400 mg was evaluated in ten healthy female volunteers. Urine was collected over six periods, i.e., 0-6 h, 6-12 h, 12-24 h, 24-48 h, 48-72 h, and 72-96 h postdose. Ofloxacin levels were assayed in all samples using a microbiological method and HPLC. Urinary ofloxacin MICs were determined for five bacterial strains recovered from urine, two E. coli strains of which one was susceptible and the other resistant to nalidixic acid (Nal-A), one Klebsiella pneumoniae resistant to nalidixic acid (Nal-B), one Staphylococcus saprophyticus strain, and one Enterococcus faecalis strain; MICs were 0.06, 0.25, 1, 0.25, and 2 mg/L, respectively. Mean urinary ofloxacin levels by the microbiological method during the six collection periods were 193.3 +/- 30.3, 138.1 +/- 31, 53.2 +/- 7.3, 8.3 +/- 0.8, 1.4 +/- 0.2, and 0.6 +/- 0.1 mg/L, respectively. HPLC provided similar results: 216.7 +/- 31.6, 130.7 +/- 20.5, 56.5 +/- 7.1, 8.3 +/- 0.9, 1.5 +/- 0.3, and 0.5 +/- 0.05 mg/L, respectively. Mean urinary ofloxacin excretion over 96 h was 67.4 +/- 3.6% of the dose by the microbiological method was 72.5 +/- 2.5% of the dose by HPLC. On the first day, bacteriostatic activity of urine against enterobacteria exceeded 32 and was greater than 8192 for the nalidixic acid-susceptible E. coli strain; on the next day, overall values were equal or greater than 8 for the nalidixic acid-resistant E. coli and K. pneumoniae strains. Bacteriostatic activity was equal to or greater than 32 for the S. saprophyticus strain during the first two days and equal to 8 on the first day and 4 on the second day for the E. faecalis strain.

Administration, Oral↗
PubMedDate not supplied

[Study of in vitro antimicrobial resistance of positive coprocultures to Shigella sp].

BACKGROUND: The gastroenteritis caused by Shigella sp (shigellosis) represents an important cause of morbimortality, especially in children under two years old. It is well known that the proper antimicrobial therapy can improve clinical state and diminish the disease dissemination. Increasing levels of resistance to drugs commonly used in the treatment of shigellosis have been described, and its sensibility has not been recently evaluated in our setting. OBJECTIVE: To evaluate the Shigella antimicrobial resistance in our setting. METHODS: A retrospective study was conducted using 106 coprocultures of patients, hospitalized or not, who have been assisted at HCPA and at HPV, during the period of 1994 to 1996, with the sensibility test done through the Kirby-Bauer technique of diffusion discs. RESULTS: Out of the 106 coprocultures studied, 35 (33%) came from HPV and 71 (67%), from HCPA. Considering the species, 58.8% were S. flexneri, 39.6%, S. sonnei, 0.9%, S. disenteriae and 0.9%, S. boydii. The resistance levels to usually indicated antibiotics were: ampicillin -57.5%, trimethropim-sulfamethoxazol -75.5%, and nalidixic acid -7.5%. CONCLUSIONS: These results show significant (p<0.001) in vitro antimicrobial resistance to ampicillin and trimethoprim-sulfamethoxazol and low resistance to nalidixic acid among Shigella sp. Thus, nalidixic acid may be an option to treat infections caused by resistant organisms.

English Abstract↗
PubMed1992

Lipid peroxidation and loss of potassium from red blood cells produced by phototoxic quinolones.

Alterations of the cationic permeability of red blood cell membranes induced by the photosensitiser nalidixic acid were demonstrated by evaluating the potassium loss from intact erythrocytes. The results show that an increase in intracellular potassium efflux, precedes the photohemolysis induced by nalidixic acid. The addition of a nonpermeable osmotic solute, such as sucrose, inhibited photohemolysis but not the potassium loss, indicating a colloid osmotic lysis. Lipid peroxidation induced by nalidixic acid and other photosensitiser quinolones (oxolinic acid and rosoxacin) was time irradiation-dependent. Although rosoxacin was the most photoperoxidative, none of the three quinolones studied produced significant lipid peroxidation. However, of the three quinolones studied, only rosoxacin considerably diminished the percentage of the cholesterol extracted from red blood cell membranes. It is postulated that the increased cation permeability induced by nalidixic and oxolinic acids cannot be attributed to cholesterol oxidation nor to lipid peroxidation; a more probable mechanism is photo-oxidation of amino acid residues of the membrane proteins. However, the lysis induced by rosoxacin is caused by photo-oxidation of cholesterol, not excluding other cellular targets.

4-Quinolones↗
PubMed2002

Comparison of the Etest and agar dilution for in vitro antimicrobial susceptibility testing of Campylobacter.

The performance of the Etest and agar dilution for in vitro antimicrobial susceptibility of Campylobacter spp. was evaluated using a quality control strain Campylobactor jejuni ATCC 33560, and 81 C. jejuni and 54 Campylobacter coli isolates recovered from retail raw meats. Seven antimicrobial agents: chloramphenicol, ciprofloxacin, doxycycline, erythromycin, gentamicin, nalidixic acid and tetracycline, were tested using the two methods, whereas azithromycin was tested using the Etest only. The correlation between the Etest and agar dilution MICs varied greatly depending on the antimicrobial agents tested. The overall agreement of MICs (+/-1 log(2) dilution) between the two methods was 61.9%, ranging from 21.4% for nalidixic acid to 92.6% for gentamicin. MICs obtained using the Etest were generally lower than those by agar dilution regardless of the species of organism tested. MIC(50) and/or MIC(90) values were at least one dilution lower for the Etest than for agar dilution when testing chloramphenicol, ciprofloxacin, doxycycline, erythromycin and nalidixic acid. Based on the agar dilution MICs, the resistant rate of the 135 Campylobacter isolates was highest for tetracycline (82.2%), followed by doxycycline (78.5%), nalidixic acid (21.5%), ciprofloxacin (20.7%) and erythromycin (17.0%). None of the isolates demonstrated resistance to chloramphenicol or gentamicin. The study indicated that the Etest results were not in complete agreement with the agar dilution test. Although the Etest has been proven to be a satisfactory testing method, its use for Campylobacter susceptibility testing requires further standardization. The study also showed that C. jejuni and C. coli isolates resistant to antimicrobials used for treating campylobacteriosis were common in retail raw meats.

Agar↗